package com.effort.com.effort.excle.core.util;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * ip 工具类
 */
public class IPUtils {

    private IPUtils(){}

    private static final IPUtils IP_UTILS = new IPUtils();


    /**
     * 获取工具类的实例
     * @return
     */
    public static final IPUtils getInstance(){
        return IP_UTILS;
    }

    /**
     * 获取用户的真实ip
     * @return
     */
    public String getIpAddr() {
        String ipAddress = null;
        //ipAddress = this.getRequest().getRemoteAddr();
        ipAddress = this.getRequest().getHeader("x-forwarded-for");
        if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = this.getRequest().getHeader("Proxy-Client-IP");
        }
        if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = this.getRequest().getHeader("WL-Proxy-Client-IP");
        }
        if(ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
            ipAddress = this.getRequest().getRemoteAddr();
            if(ipAddress.equals("127.0.0.1")){
                //根据网卡取本机配置的IP
                InetAddress inet=null;
                try {
                    inet = InetAddress.getLocalHost();
                } catch (UnknownHostException e) {
                    e.printStackTrace();
                }
                ipAddress= inet.getHostAddress();
            }

        }

        //对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
        if(ipAddress!=null && ipAddress.length()>15){ //"***.***.***.***".length() = 15
            if(ipAddress.indexOf(",")>0){
                ipAddress = ipAddress.substring(0,ipAddress.indexOf(","));
            }
        }
        return ipAddress;
    }

    private HttpServletRequest getRequest(){
        return ServletUtils.getRequest();
    }
}
